Early in The 9/11 Wars, a magisterial history of the last decade, Jason Burke describes a battle in an Iraqi town called Majar al-Kabir, held in June 2003, soon after the Anglo-American invasion of Iraq. The battle was described by press headlines in the UK as the heroic "last stand" of humanitarian-minded British soldiers against a mob of vicious Iraqi insurgents. Abruptly one morning, a British patrol in the town had found itself attacked from all sides. While they were fighting their way out, another contingent of six British soldiers entrusted with "reconstruction" found themselves trapped in a police station in another part of Majar al-Kabir. Following a short siege, when a local elder tried to negotiate safe passage for the British, angry Iraqis stormed the building. Pleading for their lives, the outnumbered British soldiers held up pictures of their wives and children, but were murdered none the less.

"I believe what I was doing was for the purpose of good," one of the executed soldiers had written in a letter to his mother to be opened in the event of his death. The soldier couldn't be faulted for claiming virtue for his side. Post 9/11, politicians and commentators in the west had, as Burke writes, insisted that "the violence suddenly sweeping two, even three, continents was the product of a single, unitary conflict pitting good against evil, the west against Islam, the modern against retrograde." The sheikhs of al-Qaida had their vision of Islam's extensive sovereignty. But as Burke points out, George Bush and Tony Blair, too, like the militant extremists, "both understood and projected the conflict as part of a cosmic contest – to propagate a series of universal principles".

From the western perspective at the time, in which Iraq was supposed to blaze the trail for freedom and democracy across the Middle East, "the violence at Majar al-Kabir appeared to defy explanation". On the face of it, the Iraqi town ought to have had no "insurgents". It was mostly Shia, a victim of Saddam Hussein's brutality, and had liberated itself soon after the invasion in 2003. There was also no clear economic provocation for the murderous fury of the Iraqis. The people fighting their British saviours were not "regime dead-enders". Nor were they the savage militants of al-Qaida in Iraq, who would help turn Iraq into the world's major killing fields between 2004 and 2006.

Rather, they were men in whom a foreign occupation army inflamed a great feeling of humiliation. The unrest in Majar al-Kabir had begun to simmer when British troops who took charge of the town from their American counterparts ignored local figures of authority and tried to impose their own rule. Their attempt to disarm the locals incited much rage, as did incidents of soldiers barging with their dogs into women's quarters. Furthermore, the Iraqis had enough historical reasons to believe that the Anglo-American invaders actually wanted the Iraqis disarmed so as to occupy their country and steal its oil. As Burke explains, the tragedy at Majar al-Kabir occurred because the foreign occupiers, though well-intentioned, had no "legitimacy" in the eyes of local Iraqis.

"They too are our cause," Blair had proclaimed after 9/11, "the starving, the wretched, the dispossessed, the ignorant, those living in want and squalor from the deserts of northern Africa to the slums of Gaza, to the mountain ranges of Afghanistan." Apprehending those responsible for the mass murder on 9/11 was also not enough for Bush, who spoke repeatedly of extending the blessings enjoyed by the west to benighted peoples across the Middle East. But such Johnny-come-lately revolutionaries had somehow contrived to miss the central fact of the 20th century (which even a quick glance at the ferocious anti-British uprising in Fallujah in 1920 could have conveyed): the ever-renewable, and often irrational, power of nationalism, the resilience and dynamism of local identities against globalising forces.

The boyish Anglo-Americans plotting to remake the world in their preferred image of the west seemed to have no idea that resentful memories of similar remakings by European imperialists define the identity and self-perceptions of many non-western societies. Contrary to the belief that 9/11 was history breaking in, the attacks actually deepened a historical solipsism in the United States and brought on a weird amnesia in post-imperial Britain. Many of these countries' "best and brightest" seemed unable to abandon the conceit that America was somehow "exceptional", immune to the dangers of moral vanity and ideological over-reaching. The faith in American virtue and good intentions cancelled out the eternal wisdom that war has its own momentum and engenders many unpredicted barbarisms – legalised torture as well as al-Qaida in Iraq and the Pakistani Taliban.

Western elites were misled, too, by their supposed victory over communism. The Lebanese-French writer Amin Maalouf sums up the powerful illusions spawned in the decade before 9/11 in his new book Disordered World: "we believed that democracy would now gradually spread until it encompassed the whole planet; the barriers between countries would fall; the movement of people, goods, images and ideas would develop unimpeded, ushering in an era of progress and prosperity."

Of this millenarian fantasy of the flattened earth, which informed war-making by western heads of state and innumerable columns by international affairs pundits as well as the average issue of the Economist, you can now only wonder: what was that all about? A series of unexpected events since 9/11 have vaporised the post-cold-war optimism that western liberal democracy, based on private property, free markets and regular elections, was the terminus of human history, a place where it was believed even Russia and China, the most intransigent of the west's recent adversaries, would soon arrive. In the wake of the great recession and two disastrous wars, the mood in the west is of sour disillusion, further exacerbated not only by periodic outbreaks of Islamist extremism but also a new assertiveness from China, Russia, India, Iran, Brazil and Turkey.

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To those disoriented by the last decade, Burke's book provides much sober information and analysis of its fiascos, which are intellectual as well as political and military. His "focus is not the decisions taken in western capitals but the effects of those decisions", especially on the more obscure "victims of this chaotic matrix of confused but always lethal wars": "the refugees who ran out of money and froze to death one by one in an Afghan winter, those many hundreds executed as 'spies' by the Taliban, those gunned down as they waited for trains home at Mumbai's main railway station one autumn evening", as well as those killed in the 9/11 strikes and the 7/7 and Madrid bombings.

Burke arranges his many stories in meaningful patterns. If you wonder why the brutal Taliban are resurgent under the banner of Pashtun nationalism in Afghanistan, it may help to remember the latter's foot soldiers, who in 2001 were crammed by pro-American warlords into container trucks, from which "the bodies spilled out like fish when they were later opened"; or, the American interrogators in Kandahar who were pouring petrol into the anuses of their Afghan prisoners long before some "bad apples" at Abu Ghraib were exposed.

It helps, too, to read about the "extended familial and tribal networks" of Afghanistan, which means "that violence against one [is] seen as violence against scores or even hundreds". As for western nation-building efforts, a more revealing clue than the much written-about follies in Baghdad's Green Zone lies in a report by the humanitarian intellectual Bernard-Henri Lévy. Compiled at great expense to the French government, it proposed that Afghanistan be exposed to "a year of French cinema".

Reporting from a range of settings - the slums of Casablanca, Afghanistan's Tora Bora mountains, the valley of Kashmir and the streets of Fallujah - Burke has witnessed the first decade of the 21st century at a level where its proclaimed slogans seem farcical, the instigators of wars, civilian and military, more absurd, and reality altogether more surreal. The long patient sentences of The 9/11 Wars are suffused with the melancholy of a man who has learned a great deal from long exposure to atrocity and folly but does not expect to be heard. Still, you feel, this account of painfully familiar events should have been prefaced with a statutory warning. Writing his 800-page play Die letzten Tage der Menschheit (The Last Days of Mankind), during the first world war, the Viennese writer Karl Kraus warned in a preface that his contemporaries would not be able to bear it – and not just because of its length. For the play was "blood of their blood", presenting as it did "those unreal, unthinkable years, out of reach for the wakeful hours of the mind, inaccessible to memory and preserved only in nightmares". So does our own low, dishonest decade seem in The 9/11 Wars.

And to relive the conflagration spanning several continents, culturally and ideologically as well as geographically; to remember their most recognisable and enduring icons – "the hooded man, the leashed man, the slavering dog inches from the face of the terrified detainee"; to recall the Guantánamo prisoners in orange jumpsuits, the retaliatory beheading of western hostages in similarly coloured clothes, the videos of London's suicide bombers, the hounding of David Kelly; to read again the mendacities of statesmen and opinion-makers is to know anger, grief and, finally, disgust.

The Great War, wrote Kraus, "was a disastrous failure of the imagination and an almost deliberate refusal to envisage the inevitable consequences of words and acts". It was "made possible above all by the corruption of language in politics and by some of the major newspapers". Burke's book shows that this is as true of 21st-century multi-theatre conflict, from the bloodthirsty rants of Osama bin Laden and Anwar al-Awlaki through the falsehoods about Iraq's WMDs in prestigious western newspapers, the martial bluster of respectable politicians and intellectuals to, most recently, the "manifesto" of the Norwegian mass murderer Anders Behring Breivik.

Early in the wars, George W Bush outlined their principal crudity: "Either you are with us," he declared soon after 9/11, insentiently mocking the universal surge of sympathy and support for the United States, "or you are with the terrorists." His assistant secretary of state threatened to bomb Pakistan "back to the stone age". "We're killin' 'em! We're killin' 'em all!" Bush exhorted his generals at a bad moment during the war in Iraq. "We are going to wipe them out. We are not blinking." This ferocity may be put down to the transferred incontinence of the "dry drunk", as Norman Mailer speculated. But even some of the most intelligent and eloquent writers in Anglo-America did not seem exempt from such megalomaniacal urges.

Certainly, the accumulating horrors and obscenities of the 9/11 wars did not bring forth an Anglo-American Sassoon or Owen for our time. Post-9/11 literature revealed some distinguished fictionists – John Updike, Don DeLillo – to be helpless before the complexities of history and ideology. Interestingly, these did not intimidate the matchless chronicler of cold-war deceptions, John le Carré; and an exceptional new debut novel, Amy Waldman's The Submission, makes you realise just how rare political intelligence, or even a shrewd worldliness, became in the prose fiction – as opposed to film – of this period. Many other writers, men born too late for the 20th century's great wars, found an easy inflation of their dormant will-to-power in what they saw as the first great martial and ideological struggle of the 21st century. "As horrible as the attack was," Waldman writes in The Submission, "everyone wanted a little of its ash on their hands."

This is true not only of the author of fiction notorious for its misogyny, who suddenly turned into a fervent advocate of the rights of Muslim women, the parodically Tory elegist of the English countryside who became a tendentious interpreter of the Koran, or the many inspiration-free hack-columnists who recycled themselves as clash-of-civilisations enthusiasts. There were also many public intellectuals itching to be in on the action. Christopher Hitchens claimed to have felt an exhilarating ideological clarity while watching the World Trade Center collapse. "Well, ha ha ha, and yah, boo," he mocked those advising against a war in Afghanistan in November 2001, while predicting that the Taliban "will soon be history". "Our culture demands respect, too," Hitchens added, and Thomas Friedman, the pre-eminent foreign affairs columnist of the United States, knew how this could be achieved. American soldiers in the Middle East needed to "take out a very big stick" and tell millions of Arabs: "Suck. On. This." The American professor Fouad Ajami, a native informant on the "Arab mind", claimed that Iraqis were "sure to erupt in joy" at the sight of American liberators. Exhorting America to impose a western empire on Asia, the historian Niall Ferguson declared himself a "fully paid-up member of the neo-imperialist gang".

At once hysterical and empty, such battle-cries define not only the dominant rhetorical style of this era but also the nature of the 9/11 wars: optimal and extensive destruction attended by minimal meaning, announcements of a cosmic contest accompanied by what Burke calls an "appalling ignorance" of the "local conditions, the circumstances and the cultures of other protagonists". Indeed, false historical analogies, loudly and repetitively asserted, replaced the attempt at knowledge. The dictator of Iraq, his name mispronounced menacingly as "Sad-Damn", was another Hitler; not removing him amounted to a second Munich. One forceful interpretation of 9/11 compared the anti-west pan-Islamism of men like Bin Laden to the totalitarian ideologies – nazism, communism, fascism – of the previous century and concluded that there was now in the world another evil called "Islamofascism", which was no less malign and potent than the other anti-liberal "isms" vanquished by the liberal-democratic west.

The blithe mixing of disparate "isms", which overlooked the sobering detail that the majority of the world's population has identified the west as much with imperialism as with liberal democracy, created a heady cocktail: the misconception, repeatedly touted as a justification behind the invasion of Iraq, that "Islamofascism" was embodied by a secular despot like Saddam Hussein as well as by Osama bin Laden, and would require a tough, generation-long battle to subdue. Not surprisingly, a large majority of Americans came to hold Saddam Hussein responsible for the 9/11 attacks.

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The sense of mad overkill, intellectual as well as military, grows more oppressive when you realise that, though al-Qaida murdered many people on 9/11 and undermined American self-esteem, the capacity of a few homicidal fanatics to seriously harm a large and powerful country such as the US was always limited. There is nothing surprising about their spectacular lack of success in rousing Muslim masses anywhere (as distinct from inciting a few no-hopers into suicidal terrorism). Their fantasy of a universal caliphate was always more likely to provoke fierce Muslim resistance than the globalising project of the west. Over-reaction to al-Qaida was by far the bigger danger to the west throughout the last decade; and, as it happened, groups of rootless conspirators, initially cultishly small and marginal, quickly proliferated around the world as a direct result of western military and ideological excesses after 9/11.

The damage to the west in the last decade has been overwhelmingly self-inflicted. Some of the domestic toll is visible in the draconian restrictions on civil liberties, the vast bureaucracy of "security" and the increased surveillance, electronic eavesdropping and other infringements of individual privacy and dignity that now seem routine and irrevocable. "War," Randolph Bourne famously warned in the early 20th century, "is the health of the state." It is now also the health of companies such as Halliburton, Blackwater (now Xe Services) and Lockheed Martin that are embedded with the state. More appallingly, war is the atrophy of the individual conscience. In The Submission, which intrepidly records the bitter spiritual aftermath of 9/11, a character laments how "afraid" everyone has been in the last decade "of appearing unpatriotic, of questioning government, leaders. Fear has justified war, torture, secrecy, all kinds of violations of rights and liberties."

This was to be expected. "The force that is wielded by men rules over them," Simone Weil wrote in her great essay on the Iliad. "The human soul never ceases to be transformed by its encounter with force – is swept on, blinded by that which it believes itself able to handle, bowed beneath the power of that which it suffers." What remains surprising is the extent to which a large majority grew callous while young men and women, like those British soldiers in Majar al-Kabir, exposed themselves, at the behest of politicians playing at world revolution and intellectuals drunk on too many mixed "isms", to an early and ignominious death.

The wars for which a small group of people in the west, essentially members of the military and their families, bore a disproportionate sacrifice were largely invisible to the rest. Unlike in the 1960s, the anti-war movement failed to animate political life; and there wasn't even a significant countervailing "support-the-troops" attempt at civic patriotism. "Why should we hear about body bags and deaths?" Barbara Bush, mother of George W, exasperatedly asked. "Why should I waste my beautiful mind on something like that?" Why indeed? The wars were kept invisible by such willed ignorance as well as governments eager not to advertise their high costs.

In fact, the cumulative effect of sparsely reported carnages immunised us against sympathy with their many faceless and speechless victims in the wider world. We were hardly aware, let alone troubled, when entire cities and ways of lives were destroyed. More than 30,000 people, nearly 10 times the number of those killed on 9/11, have died, and many centres of folk Islam destroyed, in terrorism-related attacks in Pakistan during the last decade of the war on terror. Yet Pakistan, a country with 170 million people, is little more than a shadowy battleground in the western imagination, a security and strategic imperative rather than an actual place with flesh-and-blood human beings and long histories.

Of course, America will eventually analyse away, Maalouf writes, "its Iraqi trauma", just as it did its previous bloody interventions in Asia. "Stuff happens," as Donald Rumsfeld indelibly put it. But Iraq, where most stuff happened, "will not get over its American trauma". "Its largest communities," Maalouf points out, "will have suffered hundreds of thousands of deaths; its smaller communities will never recover their place … the fate of all these minorities is sealed." Certainly, Barack Obama's emollient speeches have failed to arrest the always acute and now rapidly growing incompatibility of historical memory between the west and the Muslim world.

The 9/11 attacks provoked, as Burke points out, much "horror, shock, genuine sympathy" among Muslims everywhere. These feelings, however, were mixed with a "strong sense that the attacks were, if not legitimate in themselves, justified by the alleged misdeeds of America and Americans over recent decades." And they were quickly challenged, if not undermined, by, among other things, the widely publicised degradations of Guantánamo (described by Dick Cheney in his new memoir In My Time as "a model facility – safe, secure, and humane"), and the epidemics of anti-Muslim hatred in Europe and America.

The atrocities of thought and speech that blighted the west's intellectual and popular cultures during the 9/11 wars, dehumanising a large part of the world's population, have been steadily matched in the east. Much popular cinema, for instance, in non-western countries features a morally unhinged America. In the Pakistani worldwide hit Khuda Ke Liye(In the Name of God) (2007), a Sufi musician is brain-damaged after being subjected to, as Cheney would put it, "enhanced interrogation techniques" for over a year in American custody. Remorseless American torturers also abound in two Bollywood films, My Name Is Khan (2010) and New York (2009), which became wildly successful in Muslim countries. Turkey's biggest-ever film Valley of the Wolves: Iraq (2010) is based on a real-life incident in which American soldiers in Iraq attacked a wedding. The film then goes on to show American soldiers, commanded by a man who claims that he is doing God's will, machine-gunning a little child in front of his mother.

The world changed on 9/11: so goes the insistent, melodramatic cliché, which stops short of telling us just how, in what ways, and primarily for whom – the western novelist dazed by the irruption of history into his insulated imagination, or the hundreds of thousands killed and mutilated, orphaned and rendered homeless across three continents. In fact, the world had been changing fast all through the complacent decade before 9/11; and it changed even faster in the next decade, when the obsession in western Europe and America with the war on terror, Iran or Islam obscured very large intellectual and geopolitical shifts.

Young protesters overthrowing two of the west's staunchest post-9/11 allies in the Arab world are only the latest evidence of changes that have intensified the shock and bewilderment caused by the terrorist attacks. Rising faster than any country since the industrial revolution, China has unexpectedly emerged on the world stage, its intentions still largely unknown, its distance from western-style democracy and capitalism still considerable. New trade agreements and regional blocs – such as the one between Asean countries and China that creates the world's largest combined market – and informal groups such as Bric and G20 attest to a widespread desire to defrost the divisions of the cold war and create an international order less dependent on the United States and EU.

Globalisation, it turns out, does not lead to a flat world marked by increasing cosmopolitan openness. Rather, it sharpens old antipathies and incites new ones, while unleashing a cacophony of opposed interests and claims. This can be seen most clearly today within Europe and America, the originators of globalisation. Inequality and unemployment grow as highly mobile corporations continually move around the world in search of cheap labour, low-tax regimes and high profits, draining much-needed investment in welfare systems for ageing populations. Economic crises, bleak employment prospects and a sense of political impotence stoke a great rage and paranoia, often directed at non-white immigrants, particularly Muslims, or channelled into random criminality.

If in the last decade of worldwide violence there has been, as Burke points out, "no defeat for the west, then there has been no victory either". Its trillion-dollar wars radically shrank Washington's moral legitimacy and geopolitical influence, and also pushed it down the path to irreversible economic decline. Indeed, the country's politically listless majority finally turned against the wars in Iraq and Afghanistan not because they were morally atrocious but because they were ineptly executed, interminable and seemed, as the financial crisis deepened, wasteful.

Public disapproval of the wars, however, is hardly sufficient to roll back the culture of brutality they spawned in the last decade. Obama requires, Friedman argued in 2008, "a Dick Cheney standing over his right shoulder, quietly pounding a baseball bat into his palm". Obama has shown that he needs no such prop to maintain the essential American posture of "toughness". He has arguably expanded the Bush administration's assault on civil liberties while ordering many more executions than his predecessor by means of drone attacks in Pakistan and Afghanistan.

In May this year, an American soldier executed Bin Laden with two shots to his chest and head. "For God and country," he radioed his superiors, drawing from an old history of violence, "Geronimo, Geronimo, Geronimo." Subsequent accounts revealed that Bin Laden had been living the wretched life of a superannuated terrorist for many years. But the cinematic raid on his Pakistani burrow repaired some of the damage to American amour-propre. It also brought emotional "closure" to some, as was evident in the scenes of jubilation in the United States.

No such thing is possible for many victims of the unconscionable assaults on 9/11, whose 10th anniversary falls a week tomorrow. Nor is there any possibility of redemption for the many more lives ruined subsequently in the longest and most unsuccessful wars in America and Europe's modern history, which, ongoing and potentially endless, have yet to reveal their most devastating consequences.

An impartial reckoning with them is not something that governments can be entrusted with. And the Obama administration hasn't even tried, vapidly urging us instead to look ahead. As for those Republicans who seek to replace him in 2012, a cheap vengefulness and borderline xenophobia drive their foreign policy. They refuse to see the limitations of force, and stand ready to blame, as they did after Vietnam, all defeats on American leniency. A decade after 9/11 we seem no closer to defusing the sinister power of what Waldman describes as the "bellicose, lachrymose religion the attack had birthed" and "the fundamentalists who defended it by declaring the day sacred, the place sacred, the victims sacred, the feelings of their survivors sacred". "So much sacredness", as the novel unflinchingly points out, that there's "no limit to the profanity justified to preserve it."

Pankaj Mishra's new book, The Revenge of the East, will be published next year. To order Disordered World (Bloomsbury, £20) for £16 or The Submission (William Heinemann, £12.99) for £9.99, both with free UK p&p, call Guardian book service on 0330 333 6846 or go to guardian.co.uk/bookshop